Being on the mats is definitely a great place to use up all your aggression and negative energy. Or forget about whatever is bothering you.
I am older now, in my 50s, and not really feeling the competitive nature anymore. The mat burn, injuries, rolling with smelly people, and having my joints bent the wrong way, is not nearly as enticing as it used to be. Fortunately, I have not caught anything like ringworm or staph.
Grew up kickboxing and doing semi and full contact karate, so that is much more my bag. Hardly ever even spar that now. Content to do bag and pad work most of the time. Rather have the workout now than the conflict inherent to it. I felt differently until about two years ago. A laundry list of injuries has caught up to me, and it is time to mellow out.